enlargement & reduction

An enlargement is a transformation where the object becomes bigger or smaller to create an image.

The scale factor is the number of times bigger or smaller that the original object.

eg A scale factor of 2 means the image is twice as big as the original object.

eg A scale factor of 3 means the image is three times as big as the original object.

eg A scale factor of 1/2 or 0.5 means the image is half the size of the original object.

If the object is enlarged by a scale factor between 0 and 1 (eg 0.5, 0.25, etc), then the image gets smaller. The image has reduced in size and this is often called a reduction.

Example

Triangle ABC has been enlarged through the centre of enlargement by a scale factor of 3 to create Triangle A'B'C'.

This means Triangle A'B'C' is three times bigger than Triangle ABC.

Triangle ABC is the original object, triangle A'B'C' is the image.